Nitrogen oxides reducing aftercooler for turbocharged engines

ABSTRACT

An aftercooler apparatus that is connected to a turbocharger and to a reciprocating engine has a primary and a secondary saturation chamber, and a drying chamber. Turbocharged air from the turbocharger is directed into the primary saturation chamber. The incoming air is initially mixed with and cooled by water located at the bottom of the primary saturation chamber before being directed through a diffusion screen. The air exiting the diffusion screen enters the secondary saturation chamber where intense bubbling and foaming increases the air-water contact area to further cool the air and form an air-water mixture approaching the temperature and moisture level of saturation. The air-water mixture is then directed into the drying chamber where a majority of the moisture is removed from the air through the use of centrifugal force. The now cooler moist air is directed toward the engine intake manifold, whereby the moisture in the air stream acts to reduce the NOx formation during the combustion process. The aftercooler apparatus acts to reduce the formation of NOx emissions from turbocharged engines rather than attempting to remove the NOx emissions from the exhaust stream of the engines. The aftercooler apparatus may also be used to beneficially recycle industrial waste waters.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division of application Ser. No. 08/798,221, filed Feb. 10,1997, now U.S. Pat. No. 6,035,834.

TECHNICAL FIELD

The present invention relates to an apparatus for reducing the formationof nitrogen oxides. More precisely, it relates to an apparatus forreducing the formation of nitrogen oxides from turbocharged engines andfrom systems employing exhaust gas recirculation.

BACKGROUND OF THE INVENTION

There are apparatus' for reducing nitrogen oxides (NOx) from exhaustgases, but these apparatus' have normally been limited to the use ofwater injection systems for reducing NOx emission from the exhaust gasesof combustion engines. Water injection systems in reciprocating engineshave been used for increasing power and internal cooling, but notdirectly for reducing the formation of NOx.

Exhaust gas recirculation (EGR) has been used as a NOx reductiontechnique in reciprocating engines, but its use has been limited indiesel engines which are turbocharged and aftercooled, because normalengine aftercoolers are typically small finned core heat exchangers. Thesmall air spaces in these heat exchangers are quickly fouled by sootwhich all diesel engines emit, even if only for startup. Accordingly,there is a need for an aftercooler apparatus that would solve thetraditional aftercooler fouling problem seen with EGR systems while alsocooling the intake air and reducing the formation of NOx emissionlevels.

Further, the presently used NOx reducing devices remove gaseous orparticulate matter from the exhaust stream of an engine or apparatusthrough the use of chemical reagents, activated carbon filter elementsor exhaust gas conditioners. There is a need for a NOx reducingapparatus that reduces the formation of NOx in the engine by treatingthe intake air to the engine, thereby also affecting the combustionprocess and eliminating the need to remove the sediment formation fromNOx reducing after treatment type devices due to the concentration ofsoot or other such contaminants.

In order to overcome the above-mentioned defects in the previously knownmethods and apparatus' for reducing the NOx emissions from turbochargedengines, there is a need for an apparatus for reducing NOx emissionsfrom turbocharged engines that acts on the intake air of the engine, notthe exhaust gases, and that reduces the formation of NOx rather thanremoving it from the exhaust stream of the engine. There is also a needfor an apparatus for reducing NOx emissions from turbocharged enginesthat does not require the removal of concentrated pollutants from thetreatment device and which allows for the removal of traditional engineaftercooler devices thereby reducing air flow restriction and increasingfuel economy. There is also a need for an apparatus for reducing NOxemissions that uses water as a coolant without requiring the coolingwater to be treated for the removal of dissolved solids in the waterprior to using the water as a coolant. The apparatus of the presentinvention meeting these requirements is described in more detail below.

SUMMARY OF THE INVENTION

In accordance with the present invention, the disadvantages of the priormethods and apparatus' for reducing NOx emissions from the exhaust ofengines has been overcome. The apparatus of the present invention isenvironmentally safe, increases fuel economy, eliminates the requirementof removing concentrated pollutants produced from combustion and lowersexhaust temperature which leads to increased engine life.

According to the present invention, the apparatus consists of anaftercooler device that is connected to an engine turbocharger and to areciprocating engine. Turbocharged air from the turbocharger is directedinto the aftercooler through an inlet tube into the aftercooler'sprimary saturation chamber. The incoming air is initially mixed with andcooled by the water located at the bottom of the primary saturationchamber before being divided and directed toward and through a diffusionscreen. The air exiting the diffusion screen enters a secondarysaturation chamber where intense bubbling and foaming increases theair-water contact area that further cools the air and results in anair-water mixture approaching the temperature and moisture level ofsaturation.

The cooler and saturated air is then moved through a tangential outletinto a primary drying chamber where a majority of the moisture isremoved from the air through the use of centrifugal force. The air isthen directed toward an outlet tube that forces the air to make anabrupt 180 degree turn thereby assisting in removing any unevaporatedwater not separated from the air stream. The now cooler moist air isdirected toward the engine intake manifold, whereby the moisture in theair stream acts to reduce the NOx formation during the combustionprocess. The exhaust gas from the engine is collected in the exhaustmanifold and directed toward the turbine wheel in the turbocharger,which uses the energy in the exhaust stream to drive the turbocharger'scompressor.

Accordingly, it is the primary object of the present invention toprovide an apparatus the reduces the formation of NOx emissions fromturbocharged engines rather than removing NOx emissions from the exhauststream of the engines.

It is a further object of the present invention to provide an apparatusfor reducing NOx emissions from turbocharged engines that does notrequire the removal of concentrated pollutants from the treatment deviceand which allows for the removal of traditional engine aftercoolerdevices thereby reducing air flow restriction and increasing fueleconomy.

It is another object of the present invention to provide an apparatusfor reducing NOx emissions from turbocharged engines that acts on theintake air of the engines, not the exhaust gases, and that reduces theformation of NOx emissions rather than removing these emissions from theexhaust stream of the engines.

It is a further object of the present invention to provide an apparatusfor reducing the NOx emissions from engines that uses water as a coolantwithout requiring the cooling water to be treated for the removal ofdissolved solids in the water prior to using the water as a coolant.Other objects and advantages of this invention will become apparent fromthe following description wherein is set forth, by way of illustrationand example, certain embodiments of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a turbocharged engine system using theapparatus.

FIG. 2 is an elevational right side view of the turbocharged enginesystem depicted in FIG. 1.

FIG. 3 is an elevational front view of the turbocharged engine systemdepicted in FIG. 1.

FIG. 4 is an elevational left side view of the turbocharged enginesystem depicted in FIG. 1.

FIG. 5 is a perspective view of the apparatus shown in FIG. 1.

FIG. 6 is a longitudinal sectional view of the apparatus taken alonglines 6--6 of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, a typical embodiment of the invention isshown in FIGS. 1-6. Before the present invention is described, however,it is to be understood that this invention is not limited to aparticular or specific description. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, as the scope ofthe present invention will be limited only by the appended claims.Further, unless defined otherwise, all terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich this invention belongs.

Referring to FIGS. 1-4, a reciprocating engine 1 is shown connected tothe engine turbocharger 3 through the engine's exhaust manifold 4. Theengine 1 produces high temperature exhaust gas 5. The turbocharger 3 hasan exhaust pipe 7 that allows for a lower temperature exhaust gas 5a toleave the turbocharger 3. The turbocharger 3 also has a compressor 8that compresses filtered air 6 having an ambient temperature. Thefiltered air 6 is drawn into the compressor 8 through an inlet tube 9and is then discharged as compressed, heated air 10. The compressed,heated air 10 is directed through a discharge tube 11 to a NOx reducingaftercooler 12.

The aftercooler 12 humidifies and cools the incoming compressed heatedair 10 by direct water contact. The now moist air is directed as an airstream 13 to the engine 1 through an engine intake manifold 15 by an airtube 16. Inside the engine 1 the moisture in the air stream 13 acts toreduce the formation of NOx emissions during the combustion process inthe engine 1. The exhaust gas 5 from the engine 1 is collected in theexhaust manifold 4 and is directed to the turbine wheel 20 of theturbocharger 3. The turbocharger 3 uses the energy in the exhaust gas 5to drive the turbine wheel 20, which results in the exhaust gas 5ahaving a lower temperature. The turbocharger 3 then discharges the lowertemperature exhaust gas 5a out into the atmosphere through the exhaustpipe 7.

Through the use of the aftercooler 12, which treats the filtered air 6that is compressed and directed to the aftercooler 12 and which becomesthe intake air (the air stream 13) of the engine 1, the formation of NOxemissions is reduced. The aftercooler 12 thereby provides for a moreefficient method of reducing NOx emissions by reducing the formation ofNOx during the combustion process versus attempting to remove theseemissions from the exhaust gases 5 after being formed in the combustionprocess in an engine.

Referring now to FIGS. 1, 5 and 6, the aftercooler 12 is shown in moredetail. The aftercooler 12 consists of a two-part pressure vessel 26having a top half 27 and a bottom half 28. The discharge tube 11 of theturbocharger 3 is connected to the aftercooler's inlet air tube 25. Theinlet air tube 25 is located at the lower end 29 of the bottom half 28of the aftercooler 12. The vessel 26 is also shown to have threechambers: a primary air saturation chamber 30, a secondary airsaturation chamber 35 and a drying chamber 40. The primary airsaturation chamber 30 and the secondary air chamber 35 are located inthe bottom half 28 of the vessel 26. The drying chamber 40 is located inthe top half 27 of the vessel 26.

The secondary air saturation chamber 35 has a closed end cylinder 35athat is located immediately above the primary air saturation chamber 30and is held in place by fasteners. At the bottom of the closed endcylinder 35a is a diffusion screen 36. The closed end cylinder 35a ispositioned above the primary air chamber 30 such that the diffusionscreen 36 is directly above the entry way 45 of the inlet tube 25.

In operation, the compressed, heated air 10 enters the vessel 26 throughthe inlet air tube 25 into the primary air saturation chamber 30. Theprimary air saturation chamber 30 has a layer of water 50 located in thelower end 29 of the bottom half 28. The water 50 that with the incomingcompressed, heated air 10 causes a tremendous air-water turbulence whichleads to some of the water 50 to evaporate thereby causing thecompressed, heated air 10 to cool to form semi-cooled compressed air 51.The diffusion screen 36 while allowing the semi-cooled compressed air 51to enter into the secondary air saturation chamber 35 divides thesemi-cooled compressed air 51 into separate flows of air where intensebubbling and foaming increases the air-water contact. The additionalair-water contact further cools the semi-cooled compressed air 51 toform an air-water mixture 52 that approaches the temperature andmoisture level of saturation.

Located at the top end 53 of the closed end cylinder 35a is a tangentialoutlet tube 55 that allows the air-water mixture 52 to exit thesecondary air saturation chamber 35 and to enter the drying chamber 40.The tangential outlet tube 55 forces the air-water mixture 52 to make a90 degree turn before entering the drying chamber 40. The 90 degree turncauses the air-water mixture 52 to circulate along the interior walls ofthe drying chamber 40. Due to the resulting centrifugal force most ofthe mist 52a in the air-water mixture 52 is separated from the air-watermixture 52, thereby forming moist compressed air 56. The mist 52a isallowed to drain back into the primary saturation chamber 29 through theuse of return water passages 57.

As shown in FIGS. 1, 5 and 6, the moist compressed air 56 proceedsfurther up into the drying chamber 40 until it makes an abrupt 180degree turn as it enters the outlet air tube 60 which directs the moistcompressed air 56 out of the aftercooler 12, through the air tube 16 andinto the engine intake manifold 15. The last reversal created by theabrupt 180 degree turn works to ensure that any unevaporated water notpreviously separated in the primary drying chamber 40 will be separatedfrom the moist compressed air 56. As the moist compressed air 56 isflowing through the air tube 16, the moist compressed air 56 passes atemperature sensor 65 that provides air temperature data to a processcontrol computer 70. The computer 70 is electrically connected to aninjection water solenoid valve 75 located in a water inlet port 76 thatprovides water to the primary air saturation chamber 29. The computer 70is programmed to cycle the injection water solenoid valve 75 based onthe air temperature data provided by the temperature sensor 65. Thecomputer 70 also is programmed to activate an alarm if the airtemperature data of the moist compressed air 56 is too high or falls toolow, thereby indicating a malfunction of the aftercooler 12 which couldpotentially damage the engine 1.

The water inlet port 76 is also shown to have a water pressure regulator80 that has a gauge. The water pressure regulator 80 is modulated tomaintain the desired pressure in the make-up of the water 50 in theprimary saturation chamber 29. The desired quality of the water 50 isfurther maintained by the use of water bleed down ports 81. The waterbleed down ports 81 are located on the exterior wall of the bottom halfof the vessel and allow a portion of the mist 52a draining from thedrying chamber 40 to flow out of the vessel through the water bleed downports 81. The desired make-up of the water 50 is important because anydissolved solids in the water 50 become concentrated as the evaporationprocess takes place. Thus, the amount of solids in the water 50 isregulated by the water bleed down ports 81. The rate of the flow throughthe water bleed down ports 81 is in turn regulated by the size of thehose 82 that is connected to the water bleed down ports 81 and thelocation of the bleed down ports 81 along the exterior wall of thebottom half of the vessel 26. Note, however, that the water inlet port76 which provides the water 50 to the primary air saturation chamber 29does not have to have a treatment system to first treat the incomingwater, nor does the incoming water have to be pretreated.

Thus, the aftercooler 12 can function as a NOx reducing aftercoolerusing water 50 as a coolant with water 50 having high levels ofdissolved solids. The quantity of the water 50 required for theaftercooler 12 to function properly is approximately equivalent to 20 to25 percent of the volume of water required if after-treatment NOxdevices were used. With the present invention, the use of the waterbleed down ports 81, along with the computer 70, work to provide andmaintain the desired quality of the make-up of the water 50 to providethe moist compressed air 55 for the engine 1. The resulting use of theaftercooler provides that a much less water volume level is required andconsumed for the aftercooler 12 to operate and aid in the reduction inthe formation of NOx emissions.

Additionally, the aftercooler 12 can be used with industrial wastewaters that contain specific volatiles in limited concentrations. Thevolatiles in the industrial waste waters will be destroyed during thecombustion process after the waste waters have been used to form themoist compressed air 56 for the engine 1. Examples of such waste watersinclude water contaminated with small quantities of gasoline or dieselfuel.

Further, the aftercooler 12 can be used to concentrate and recovervarious products from industrial waste waters or low concentrationindustrial product streams that contain commercially valuable substancesin concentration too low to otherwise be valuable. The aftercooler 12can operate to concentrate these substances to a level where furtherrecovery is economically viable. Examples include water contaminated bysmall quantities of glycol or antifreeze.

The aftercooler 12 can also be used in conjunction with exhaust gasrecirculation systems to further reduce the formation of NOx emissionsduring a combustion process. In this application, a small amount ofcombustion gas is intentionally mixed with the incoming air stream 6 toprovide a more nonreactive mass in the combustion mixture and therebyfurther reduce the formation of NOx emissions.

SUMMARY

The aftercooler 12 receives compressed, heated air 10 from aturbocharger 3 that is connected to a reciprocating engine 1. Theaftercooler 12 consists of a two-part pressure vessel 26, with the tophalf 27 of the vessel 26 containing the drying chamber 40 and the bottomhalf 28 containing the primary air saturation chamber 30 and thesecondary air saturation chamber 35. The compressed, heated air 10 firstenters the aftercooler 12 through the inlet air tube 25 and into theprimary air saturation chamber 30. The primary air saturation chamber 30has a layer of water 50 that with the incoming compressed, heated air 10causes an air-water turbulence to occur which leads to some of the water50 being evaporated, thereby causing the air 10 to cool and form asemi-cooled compressed air 51. A diffusion screen 36 is located abovethe primary air saturation chamber 30 and allows the semi-cooledcompressed air 51 to exit the primary air saturation chamber 30 and toenter the secondary air saturation chamber 35, where bubbling andfoaming increases the air-water contact. This additional air-watercontact further cools the semi-cooled compressed air 51 and forms anair-water mixture 52 that approaches the temperature and moisture levelof saturation.

The air-water mixture 52 exits the secondary air saturation chamber 35through a tangential outlet tube 55, which directs the air-water mixture52 to enter the drying chamber 40. The tangential outlet tube 55 forcesthe air-water mixture 52 to make a 90 degree turn before entering thedrying chamber 40. The 90 degree turn causes the air-water mixture 52from the tube to circulate along the interior walls of the dryingchamber 40, which results in centrifugal force acting to separate themist 52a from the air-water mixture 52, thereby forming moist compressedair 56. The separated mist 52a is allowed to drain back into the primarysaturation chamber 29 through the use of water return passages 57.

The moist compressed air 56 circulates further up into the dryingchamber 40 until is makes an abrupt 180 degree turn into an outlet airtube 60 which directs the moist compressed air 56 out of the aftercooler12 through the air tube 16 and into the engine air intake manifold 15.The last reversal created by the abrupt 180 degree helps to separate anyunevaporated water from the moist compressed air 56. As the moistcompressed air 56 enters the engine intake manifold 15, it is directedinside the engine 1 where the moisture in the moist compressed air 56acts to reduce the NOx formation during the combustion process in theengine 1. The exhaust gas 5 from the engine 1 is collected in theexhaust manifold 4 and directed to the compressor 8 of the turbocharger3, which uses the energy in the exhaust gas 5 to drive the turbocharger3.

It is to be understood that while certain forms of this invention havebeen illustrated and described, the invention is not limited thereto,except insofar as such limitations are included in the following claims.

What is claimed and described to be secured by Letters Patent is asfollows:
 1. A system for reducing the formation of nitrogen oxidesduring the combustion process in a turbocharged engine, said enginehaving an intake manifold and a turbocharger for supplying compressedair to said intake manifold, said system comprising:a. means forincreasing moisture within said compressed air to produce moistcompressed air, disposed between said turbocharger and said intakemanifold and being in fluid communication with said turbocharger andsaid intake manifold; b. wherein said moist compressed air is effectiveto reduce said formation of said nitrogen oxides during said combustionprocess; c. wherein said means for increasing moisture within saidcompressed air includes a saturation chamber having a lower portion anda water supply disposed in said lower portion of said saturation chambersuch that when said compressed air is introduced into said saturationchamber, a portion of said water supply evaporates to increase moisturewithin said compressed air; and d. a drying chamber in fluidcommunication with said means for increasing moisture, said dryingchamber having means for producing an air-water mixture having atemperature and moisture level approximate to that of saturation.
 2. Asystem for reducing the formation of nitrogen oxides during thecombustion process in a turbocharged engine, said engine having anintake manifold and a turbocharger for supplying compressed air to saidintake manifold, said system comprising:a. means for increasing moisturewithin said compressed air to form moist compressed air, disposedbetween said turbocharger and said intake manifold and being in fluidcommunication with said turbocharger and said intake manifold; b.wherein said moist compressed air is effective to reduce the formationof said nitrogen oxides during said combustion process; c. wherein saidmeans for increasing moisture within said compressed air includes asaturation chamber having a lower portion and a water supply disposed insaid lower portion of said saturation chamber such that when saidcompressed air is introduced into said saturation chamber, a portion ofsaid water supply evaporates to increase moisture within said compressedair, said means for increasing moisture content of said compressed airhaving a water inlet in fluid communication with said lower portion ofsaid saturation chamber for selective introduction of water into saidlower portion; d. a drying chamber in fluid communication with saidmeans for increasing moisture, said drying chamber having means forproducing an air-water mixture having a temperature and moisture levelapproximate to that of saturation; and e. an outlet in communicationwith said drying chamber and said intake manifold for delivering saidair-water mixture to said intake manifold.
 3. The system as set forth inclaim 2 further comprising temperature sensing means for determining thetemperature of said moist compressed air, means for regulating the flowof water to said water inlet, and a computer electrically connected tosaid temperature sensing means and said means for regulating, whereinsaid temperature sensing means is disposed within said outlet, saidmeans for regulating is connected to said water inlet and said computeris programmable to operate said means for regulating flow depending uponsaid temperature of said moist compressed air.
 4. A system for reducingthe formation of nitrogen oxides during the combustion process in aturbocharged engine, said engine having an intake manifold and aturbocharger for supplying compressed air to said intake manifold, saidsystem comprising:a. an aftercooler apparatus disposed between saidturbocharger and said intake manifold and being in fluid communicationwith said turbocharger and said intake manifold, said aftercoolerapparatus having a water inlet, a saturation chamber having a lowerportion and a water supply in said lower portion of said saturationchamber such that when said compressed air is introduced into saidsaturation chamber, a portion of said water supply evaporates toincrease moisture within said compressed air, an outlet, and a dryingchamber in communication with said outlet, said water inlet being influid communication with said lower portion of said saturation chamber,said saturation chamber having means for increasing moisture within saidcompressed air disposed therein to form moist compressed air, said meansfor increasing moisture within compressed air being in fluidcommunication with said drying chamber, and said drying chamber havingmeans for producing an air-water mixture having a temperature andmoisture level approximate to that of saturation, wherein said outletdelivers said air-water mixture to said intake manifold; and b. whereinsaid air-water mixture is effective to reduce the formation of saidnitrogen oxides during said combustion process.
 5. The system as setforth in claim 4 further comprising temperature sensing means fordetermining the temperature of said moist compressed air, means forregulating the flow of water to said water inlet, and a computerelectrically connected to said temperature sensing means and said meansfor regulating, wherein said temperature sensing means is disposedwithin said outlet, said means for regulating is connected to said waterinlet and said computer is programmable to operate said means forregulating flow depending upon said temperature of said moist compressedair.
 6. A system for reducing the formation of nitrogen oxides duringthe combustion process in a turbocharged engine, said engine having anintake manifold and a turbocharger for supplying compressed air to saidintake manifold, said system comprising:a. means for increasing moisturewithin said compressed air to form moist compressed air, disposedbetween said turbocharger and said intake manifold and being in fluidcommunication with said turbocharger and said intake manifold; b.wherein said moist compressed air is effective to reduce the formationof said nitrogen oxides during said combustion process; c. wherein saidmeans for increasing moisture within said compressed air includes asaturation chamber having a lower portion and a water supply disposed insaid lower portion of said saturation chamber such that when saidcompressed air is introduced into said saturation chamber, a portion ofsaid water supply evaporates to increase moisture within said compressedair, said means for increasing moisture content of said compressed airhaving a water inlet in fluid communication with said lower portion ofsaid saturation chamber for selective introduction of water into saidlower portion; d. a drying chamber in fluid communication with saidmeans for increasing moisture, said drying chamber having means forproducing an air-water mixture having a temperature and moisture levelapproximate to that of saturation; and e. an outlet in communicationwith said drying chamber and said intake manifold for delivering saidair-water mixture to said intake manifold; f. temperature sensing meansdisposed in said outlet for determining the temperature of said moistcompressed air; g. means for regulating the flow of water to said waterinlet wherein said means for regulating is attached to said water inlet;and h. a computer electrically connected to said temperature sensingmeans and said means for regulating, said computer being programmable tooperate said means for regulating flow depending upon said temperatureof said moist compressed air.
 7. A system for reducing the formation ofnitrogen oxides during the combustion process in a turbocharged engine,said engine having an intake manifold and a turbocharger for supplyingcompressed air to said intake manifold, said system comprising:a. meansfor increasing moisture within said compressed air to form moistcompressed air, disposed between said turbocharger and said intakemanifold and being in fluid communication with said turbocharger andsaid intake manifold; b. wherein said moist compressed air is effectiveto reduce the formation of said nitrogen oxides during said combustionprocess; c. wherein said means for increasing moisture within saidcompressed air includes a saturation chamber having a lower portion anda water supply disposed in said lower portion of said saturation chambersuch that when said compressed air is introduced into said saturationchamber, a portion of said water supply evaporates to increase moisturewithin said compressed air, said means for increasing moisture contentof said compressed air has a water inlet in fluid communication withsaid lower portion of said saturation chamber for selective introductionof water into said lower portion; d. a drying chamber in fluidcommunication with said means for increasing moisture, said dryingchamber having means for producing an air-water mixture having atemperature and moisture level approximate to that of saturation; e. anoutlet in communication with said drying chamber and said intakemanifold for delivering said air-water mixture to said intake manifold;f. a temperature sensor disposed within said outlet, whereby thetemperature of said moist compressed air may be determined; g. asolenoid valve connected to said water inlet for regulating the flow ofwater thereto; and h. a computer electrically connected to saidtemperature sensor and said solenoid valve, said computer beingprogrammable to operate said solenoid valve to regulate the flow ofwater to said inlet responsive to the temperature of said moistcompressed air.
 8. A system for reducing the formation of nitrogenoxides during the combustion process in a turbocharged engine, saidengine having an intake manifold and a turbocharger for supplyingcompressed air to said intake manifold, said system comprising:a. anaftercooler apparatus disposed between said turbocharger and said intakemanifold and being in fluid communication with said turbocharger andsaid intake manifold, said aftercooler apparatus having a water inlet, asaturation chamber having a lower portion and a water supply in saidlower portion of said saturation chamber such that when said compressedair is introduced into said saturation chamber, a portion of said watersupply evaporates to increase moisture within said compressed air, anoutlet, and a drying chamber in communication with said outlet, saidwater inlet being in fluid communication with said lower portion of saidsaturation chamber, said saturation chamber having means for increasingmoisture within said compressed air disposed therein to form moistcompressed air, said means for increasing moisture within compressed airbeing in fluid communication with said drying chamber, and said dryingchamber having means for producing an air-water mixture having atemperature and moisture level approximate to that of saturation,wherein said outlet delivers said air-water mixture to said intakemanifold; b. wherein said air-water mixture is effective to reduce theformation of said nitrogen oxides during said combustion process; c.temperature sensing means disposed in said outlet for determining thetemperature of said moist compressed air; d. means for regulating theflow of water to said water inlet wherein said means for regulating isattached to said water inlet; and e. a computer electrically connectedto said temperature sensing means and said means for regulating, saidcomputer being programmable to operate said means for regulating flowdepending upon said temperature of said moist compressed air.